Wnt/β-catenin通路及靶基因c-myc在肝细胞癌组织中的表达

目的 观察Wnt通路激活在肝细胞癌起源中的作用.方法 应用免疫组织化学方法检测31例肝细胞癌患者肿瘤组织(实验组)与癌旁正常组织(对照组)中Wnt2、β-catenin及其靶基因c-myc的表达.结果 在肿瘤组织与癌旁正常组织中,Wnt2蛋白的表达差异无统计学意义(P＞0.05);β-catenin的胞质表达在癌旁组织中明显增高(P＜0.05),而其胞核表达则在肿瘤组织中增高(P＜0.05);c-myc在肿瘤组织中表达增高,两组差异有统计学意义(P＜0.01).结论 β-catenin及其靶基因c-myc在肝细胞癌组织中表达增高,提示Wnt通路激活的过程在肝细胞癌的起源中起到重要作用.

Abstract：

Objective To explore the effect of Wnt signaling pathway activation in the origination of hepatocellular carcinoma. Methods Immunohistochemistry was used to observe the expression of Wnt2,β-catenin and target gene c-myc in hepatocellular carcinoma (experimental group) and peficancerous tissue (control group) from 31 patients. Results The expression of Wnt2 had no significantly difference in both groups (P ＞0. 05). The expression of β-catenin in cytoplasm was significantly higher in peficancerous tissue. However,the expression of β-catenin in nucleus was significantly higher in hepatocellular carcinoma ( P ＜ 0. 05). The expression of c-myc was also significantly higher in hepatocellular carcinoma (P ＜ 0. 01).Conclusion β-catenin and it' s target gene c-myc overexpressed in hepatocellular carcinoma. The activation of Wnt signaling pathway played an important role in the origination of hepatocellular carcinoma.     

KiSS-1、KiSS-1R及MMP-9表达与肝细胞癌侵袭转移的关系及意义

目的 检测肿瘤转移抑制基因KiSS-1及其配体KiSS-1R和基质金属蛋白酶-9(MMP-9)在肝细胞癌(HCC)中的表达,探讨KiSS-1表达与肝细胞癌侵袭转移的关系及其机制.方法 利用逆转录聚合酶链反应(RT-PCR)技术,检测HCC、癌旁肝组织及远癌肝组织中KiSS-1、KiSS-1R mRNA的表达情况;应用HCC组织芯片,结合免疫组化及彩色图像分析技术检测了KiSS-1、MMP-9蛋白在HCC芯片中各组织的相对表达量.结果 KiSS-1 mRNA在HCC中表达明显低于癌旁、远癌肝组织(P＜0.01).在转移组和临床Ⅲ期HCC中,KiSS-1蛋白的表达明显低于无转移及临床分期Ⅰ和Ⅱ期HCC(P＜0.01);KiSS-1在肝内转移灶中的表达量显著低于原发灶(P＜0.01).在转移组的HCC中,MMP-9表达量显著高于无转移的HCC(P＜0.01).在HCC组织中,KiSS-1和MMP-9的表达呈负相关性(r=-0.340,P＜0.01).结论 KiSS-1和MMP-9的表达失衡与HCC侵袭转移有关,KiSS-1的缺失表达可作为预测HCC转移潜能的有价值的参考指标.

Abstract：

Objective To detect the expression of KiSS-1, KiSS-1R and MMP-9 in hepatocellular carcinoma (HCC). To study the correlation of KiSS-1, KiSS-1R and MMP-9 expression with invasion and metastasis of HCC, and to explore the underlying mechanisms. Methods The expression of KiSS-1 , KiSS-1R mRNA in 33 HCC samples, 26 non-neoplastic adjacent liver tissue samples and 13 non-neoplastic distant liver tissue samples were detected by RT-PCR. Tissue chips were constructed by modified manual tools, which contained HCC, non-neoplastic adjacent liver tissues, non-neoplastic distant liver tissues, normal liver tissues and intrahepatic metastasis lesions. The expression of KiSS-1 and MMP-9 protein was determined by tissue chips, immunohistochemistry and semi-quantitative image analysis in 150 HCC, 137 non-neoplastic adjacent liver tissue, 98 non-neoplastic distant liver tissues, 16 normal liver tissues and 37 intrahepatic metastasis lesion samples. Results The results of RT-PCR showed that compared with the non-neoplastic adjacent liver tissues and the non-neoplastic distant liver tissues, the expression of KiSS-1 mRNA in HCC was significantly lower (P＜0.01). The expression of KiSS-1R mRNA did not changed in HCC and non-neoplastic liver tissues (P＞0.05). The expression of KiSS-1 protein was lower in HCC with metastasis and in clinical stage Ⅲ than that in those with non-metastasis, and in clinical stages Ⅰ and Ⅱ . It was also higher in the primary than in the metastasis lesions (P＜0.01, respectively). The expression of MMP-9 was higher in tumors having peplos invasion and metastasis than in those with negative peplos invasion and non-metastasis. It was lower in the primary than the metastasis lesions (P＜0. 01, respectively).Negative correlation between KiSS-1 and MMP-9 expression was found in HCC(r=- 0.340,P＜0.01). Conclusions The imbalance between KiSS-1 and MMP-9 expression might play an important role in enhancing the invasive and metastatic capacity of HCC. Loss of KiSS-1 expression might predict an aggressive clinical behavior and was associated with metastatic potential in HCC.     

上皮钙黏素1基因启动子甲基化对结肠癌上皮钙黏素和β-连接素表达的影响

目的 探讨上皮钙黏素基因(CDH1)启动子甲基化与结肠癌上皮钙黏素(E-cadherin)及β-连接素(β-catenin)的表达及临床病理特征的关系.方法 采用甲基化特异性PCR技术检测68例结肠腺癌组织、癌旁组织及正常黏膜组织中CDH1基因启动子甲基化的状况.采用免疫组织化学法检测E-cadherin及β-catenin蛋白的表达.结果 癌旁组织及癌组织中CDH1启动子甲基化的阳性表达分别为32.4%(22/68)、57.4%(39/68),正常组织均为阴性表达(P<0.05).E-cadherin在正常组织、癌旁组织及腺癌组织中阳性表达率分别为92.6%、66.2%和44.1%.正常组织中β-catenin均表达于细胞膜上,无胞质和(或)胞核表达,而β-catenin在癌旁组织及癌组织中胞质和(或)胞核表达分别为29.4%和50.0%.CDH1基因启动子甲基化阳性率与E-cadherin表达则呈负相关(r=-0.312,P=0.01),与β-catenin胞质和(或)胞核表达呈正相关(r=0.309,P=0.018).CDH1基因启动子甲基化及E-cadherin、β-catenin的异常表达均与结肠癌分化程度及转移密切相关(P<0.05).结论 CDH1基因启动子甲基化可能是导致结肠癌E-cadherin与β-catenin异常表达及肿瘤侵袭性增强的重要原因.

Abstract：

Objective To investigate the relationship between methylation of the CDH1 gene promoter on the expression of E-cadherin and β-catenin, and to evaluate the correlation with clinicopathological characteristics of the colonic carcinoma. Methods Methylation specific PCR (MSP) was used to detect CDH1 gene promoter methylation in the cancer tissue, adjacent tissues and normal tissues in 68 patients. The expression of E-cadherin and β-catenin was determined by immunohistochemistry staining. Results The positive rate of CDH1 gene promoter methylation was 32.4% in adjacent tissues and 57.4% in cancer tissue, while no detectable methylation was found in all the normal tissues. The difference was statistically significant. The positive rate of E-cadherin was 92.6% in the normal tissues, 66.2% in the adjacent tissues and 44.1% in the cancer tissues. In all normal tissues, β-catenin was expressed only at the cellular membrane but not in the cytosol or nucleus, while the expression of β-catenin was present in the cytosol or nucleus in 29.4% of the adjacent tissues and 50.0% of the cancer tissues. The positive rate of CDH1 gene promoter methylation was negatively correlated with E-cadherin expression (r =-0.312,P =0.01) and positively correlated with β-catenin cytosolic/nucleus expression(r=0.309,P=0.018). The differentiation and metastasis of colonic carcinoma were associated with the aberrant expression of E-cadherin, β-catenin, and methylation of CDH1 promoter (P<0.05). Conclusion CDH1 gene promoter methylation may lead to aberrant expression of E-cadherin and β-catenin in colonic carcinoma, and may play an important role in promoting the invasion of tumor.     

CIP4在肾间质纤维化中的表达及作用

Objective To observe the expression and localization of CIP4 (Cdc42 interacting protein-4) in the renal fibrosis and the effect of CIP4 on the expression of E-cadherin,vimentin and β-catenin tyrosine phosphorylation. Methods In vitro, the human tubular epithelial cells (HK-2 cell line) were cultured with 10 μg / L TGF-β1 for 72 h. The protein expressions of CIP4, E-cadherin, vimentin and β-catenin tyrosine phosphorylation were measured by Western blotting; the expression of CIP4 mRNA was detected by RT-PCR. The intracellular distribution of CIP4 was observe by confocal microscope. In vivo, Masson staining was used to evaluate the level of renal fibrosis; the expression and distribution of CIP4 in renal tissue were detected by immunohistochemistry. HK-2 cells were transfected with pcDNA3. 1-CIP via lipofectamine 2000. The expressions of E-cadherin, vimentin and β-catenin tyrosine phosphorylation level in the transfected cells were detected by Western blotting. Results The expressions of CIP4 mRNA and protein were up-regulated in renal tubular EMT cells. Most of CIP4 protein localized in cell membrane, and some was in cytoplasm. After stimulation by TGF-β1, the expression of CIP4 protein both in cytoplasm and nucleus was greatly increased (P ＜0.05),especially in cytoplasm. In vivo, CIP4 was expressed in renal tubular epithelia, but little expressed in glomeruli. In renal from 5/6 nephrectomized rats, CIP4 expression was significantly increased. In the CIP4 transfectants, the expression of CIP4, vimentin and β-catenin tyrosine phosphorylation level were up-regulated (P ＜0.05), but E-cadherin expression was suppressed (P ＜0.05).Conclusion The overexpression of CIP4 is likely to take part in the epithelial-to-mesenchymal transition process, thereby promoting the renal fibrosis.     

CIP4在肾间质纤维化中的表达及作用

Objective To observe the expression and localization of CIP4 (Cdc42 interacting protein-4) in the renal fibrosis and the effect of CIP4 on the expression of E-cadherin,vimentin and β-catenin tyrosine phosphorylation. Methods In vitro, the human tubular epithelial cells (HK-2 cell line) were cultured with 10 μg / L TGF-β1 for 72 h. The protein expressions of CIP4, E-cadherin, vimentin and β-catenin tyrosine phosphorylation were measured by Western blotting; the expression of CIP4 mRNA was detected by RT-PCR. The intracellular distribution of CIP4 was observe by confocal microscope. In vivo, Masson staining was used to evaluate the level of renal fibrosis; the expression and distribution of CIP4 in renal tissue were detected by immunohistochemistry. HK-2 cells were transfected with pcDNA3. 1-CIP via lipofectamine 2000. The expressions of E-cadherin, vimentin and β-catenin tyrosine phosphorylation level in the transfected cells were detected by Western blotting. Results The expressions of CIP4 mRNA and protein were up-regulated in renal tubular EMT cells. Most of CIP4 protein localized in cell membrane, and some was in cytoplasm. After stimulation by TGF-β1, the expression of CIP4 protein both in cytoplasm and nucleus was greatly increased (P ＜0.05),especially in cytoplasm. In vivo, CIP4 was expressed in renal tubular epithelia, but little expressed in glomeruli. In renal from 5/6 nephrectomized rats, CIP4 expression was significantly increased. In the CIP4 transfectants, the expression of CIP4, vimentin and β-catenin tyrosine phosphorylation level were up-regulated (P ＜0.05), but E-cadherin expression was suppressed (P ＜0.05).Conclusion The overexpression of CIP4 is likely to take part in the epithelial-to-mesenchymal transition process, thereby promoting the renal fibrosis.     

DNA甲基转移酶在肝癌中的表达及其临床意义

目的 探讨DNA甲基转移酶(DNMTs)在肝癌中的表达及其临床意义.方法 收集2007年7月至2008年4月中山大学附属第一医院行根治性切除的50例肝癌患者的肝癌组织、癌旁组织、肝硬化组织和慢性肝炎组织.采用RT-PCR和免疫组织化学方法检测肝癌组织及癌旁组织中DNMT1、DNMT3a、DNMT3b mRNA与蛋白表达水平,采用配对t检验和Mann-Whitney U检验比较肝癌组织与癌旁组织,肝硬化组织与慢性肝炎组织DNMTs mRNA表达的差异,x2检验和Fisher确切概率法分析肝癌组织DNMTs蛋白表达与临床病理因素的相关性,Kaplan-Meier法分析患者无瘤生存时间,不同患者无瘤生存时间的比较采用Log-rank检验.结果 肝癌组织中DNMT1、DNMT3a、DNMT3b mRNA的表达水平分别为癌旁组织的2.57、2.29和4.86倍(t=3.94,2.72,4.06,P＜0.05).肝癌组织中DNMT1、DNMT3a、DNMT3b mRNA的表达分别是肝硬化组织和慢性肝炎组织的2.38、2.14、4.66倍和6.12、4.58、12.99倍.DNMT1、DNMT3a、DNMT3b mRNA在肝癌组织的表达显著高于其在肝硬化组织和慢性肝炎组织中的表达(U=587.5、730.0、562.5,65.5、64.5、71.0,P＜0.05).DNMT1蛋白表达与肿瘤大小、数目、有无血管侵犯、TNM分期有关(x2=5.24,4.08,4.08,14.13,P＜0.05);DNMT3a蛋白表达与肿瘤大小、数目、TNM分期有关(x2=4.08,5.95,4.08,P＜0.05).DNMT1和DNMT3a低表达者平均肿瘤复发时间分别为9.4个月和8.7个月,显著长于高表达者的5.0个月和3.2个月,两者比较,差异有统计学意义(x2=3.89,9.91,P＜0.05).结论 DNMTs在肝癌发生、发展中起重要作用;DNMT1与DNMT3a高表达与肿瘤切除术后复发密切相关,可望成为肝癌预后的重要预测因子.

Abstract：

Objective To investigate the expression of DNA methyltransferases (DNMTs) in liver cancer and its clinical significance. Methods The specimens of liver cancer tissues, adjacent tissues, cirrhotic tissues and chronic hepatitis tissues were collected from 50 patients who received radical resection at the First Affiliated Hospital of Sun Yat-Sen University from July 2007 to April 2008. The mRNA and protein expressions of DNMT1,DNMT3a and DNMT3b in liver cancer tissues, adjacent tissues, cirrhotic tissues and chronic hepatitis tissues were detected by real-time quantitative PCR and immunohistochemical staining. The mRNA expression of DNMTs in the liver cancer tissues was compared with those in the adjacent tissues, cirrhotic tissues and chronic hepatitis tissues by using t test and Mann-Whitney U test. The correlation between the protein expression of DNMTs in the liver cancer tissue and the clinicopathological features was analyzed by chi-square test or Fisher exact test, and the tumor-free survival time was analyzed by using Kaplan-Meier method and the difference in tumor-free survival rate between different patients was analyzed by Log-rank test. Results The mRNA expressions of DNMT1, DNMT3a and DNMT3b in the liver cancer tissue were 2.57, 2.29 and 4.86 times higher than those in the adjacent tissues (t = 3.94, 2. 72, 4. 06, P ＜ 0.05 ). The mRNA expressions of DNMT1, DNMT3a and DNMT3b were 2.38,2.14 and 4.66 times higher than those in the cirrhotic tissues, and 6.12, 4.58 and 12.99 times higher than those in the chronic hepatitis tissues. The mRNA expressions of DNMT1, DNMT3a and DNMT3b in the liver cancer tissue were significantly higher than those in the cirrhotic tissues and chronic hepatitis tissues ( U = 587.5,730. 0,562.5; 65.5, 64.5, 71.0, P ＜ 0.05). The protein expression of DNMT1 was correlated with the size, number,TNM stages and vascular invasion of tumors ( x2 = 4.08, 5.95, 4.08, P ＜ 0.05 ). The protein expression of DNMT3a was correlated with the size, number and TNM stages of tumors (x2 = 4.08, 5.95, 4.08, P ＜ 0.05 ).The mean tumor recurrence time of patients with low expressions of DNMT1 and DNMT3a were 9.4 and 8.7 months, which were significantly longer than 5.0 and 3.2 months of those with high expressions of DNMT1 and DNMT3a (x2 =3.89, 9.91, P＜0.05). Conclusions DNMTs play an important role in hepatocarcinogenesis.High expressions of DNMT1 and DNMT3a are correlated with the postoperative recurrence of liver cancer, which are valuable prognostic factors for liver cancer.     

ABCG2蛋白在肝癌中表达的临床意义

Objective To investigate the expression and clinical significance of ABCG2 protein in hepato-cellular carcinoma (HCC). Methods Specimens of HCC were collected at The First Aifiliated Hospital of Sun Yat-sen University from January 2005 to December 2006. The expression of ABCG2 protein in 165 samples of HCC tissue, 25 samples of normal liver tissue and 40 samples of cirrhotic liver tissue was detected using immunohisto-chemistry. The correlation between the expression of ABCG2 protein and clinicopathological characters was then analyzed. Enumeration data, survival rate and the difference between groups were analyzed with a chi-square test, the Kaplan-Meier method and Log-rank test, respectively. Results ABCG2 protein expression was weakly posi-tive in all normal and cirrhotic liver tissues. In HCC tissues, the expression of ABCG2 protein was strongly positive in 66 cases and weakly positive in 99 cases. The expression of ABCG2 protein was related to tumor diameter, tumor number, adjacent organ invasion and TNM stages (χ2 =8. 130, 14. 279, 4. 820, 21. 179, P <0. 05). Kaplan-Meier survival analysis revealed that patients with strongly positive ABCG2 protein had a significantly lower 3-year overall survival (24. 1%) compared with those with weakly positive ABCG2 protein (39. 4%) (χ2 = 15.716, P<0.05). Conclusions The expression level of ABCG2 protein is related to tumor invasiveness, TNM stage and prognosis. ABCG2 has the potential to become a new target for HCC treatment.     

Wnt/β-Catenin信号通路在肝癌发生中的分子机制研究

目的探讨Wnt/β-Catenin信号通路在肝癌细胞增殖、迁移方面的影响和其在肝癌发生发展中的可能作用。方法体外培养HepG2和L02细胞,采用免疫荧光和Western Blot检测Wnt/β-catenin信号通路关键蛋白β-catenin、GSK3β、cyclin D1和c-myc蛋白的表达水平。培养的HepG2细胞分别用浓度100ng/ml的Wnt3α和20 ng/ml的DKK1处理,采用CCK-8检测细胞增殖活力,流式细胞实验检测细胞周期,Western Blot检测β-catenin、GSK3β、cyclin D1和c-myc蛋白的表达水平,Trans-well检测HepG2的迁移情况。结果与正常肝细胞L02相比,HepG2细胞高表达β-catenin,cyclin D1和c-myc,低表达GSK3β。Wnt3α能够显著促进HepG2细胞的增殖活力,而DKK1能够显著抑制其增殖。与Wnt3α组相比,DKK1处理组细胞G0/G1期细胞比例增加,(68.6±0.5)%VS(47.5±1.5)%(P0.01),而S期细胞比例减少(17.4±0.5)%VS(28.6±0.5)%,(P0.01)。Western Blot检测结果说明,Wnt3α提高了β-catenin、cyclin D1和c-myc的表达水平,抑制了GSK3β的表达,而DKK1抑制了β-catenin、cyclin D1和c-myc的表达。迁移实验透膜细胞数对照组为(176.40±12.98)、Wnt3α组为(238.20±18.38)、DKK1组为(110.40±9.46),P0.05。结论 Wnt/β-catenin信号通路在促进HepG2细胞的增殖和迁移方面起重要作用,在肝癌的发生发展和转移中起着重要的作用,是肝癌发生的重要分子机制。     

N-cadherin、 β-连环素在肝癌组织中的表达及与Wnt信号途径的关系

目的 观察肝癌(HCC)中N-cadherin分子是否调控β-连环素(β-catenin)的表达及Wnt信号途径的活化。方法 免疫组织化学分析64例肝癌组织中N-cadherin及β-catenin的表达及相互关系。调控肝癌细胞株HCCLM3、SMMC-7721中N-cadherin表达并检测β-catenin的表达及Wnt信号途径的活化。结果 64例肝癌中,N-cadherin表达缺失34例;β-catenin在细胞膜上表达,无细胞核内聚集,且13例细胞膜表达缺失;细胞膜上β-catenin表达缺失与N-cadherin表达缺失呈正相关(P＜0.05)。下调HCCLM3细胞或上调SMMC-7721细胞中的N-cadherin表达导致细胞膜上β-catenin表达减弱或增强,但均未导致Wnt信号途径的活化。结论 在肝癌中,N-cadherin表达与细胞膜上β-catenin的表达水平呈正相关,但N-cadherin分子并不参与Wnt信号途径的调控。     

抑制肝癌细胞β-catenin表达能降低缺氧诱导的侵袭转移潜能

目的 研究β-catenin表达对缺氧环境中肝癌细胞侵袭转移潜能的影响.方法 利用100 μmol/L氯化钴处理高转移性MHCC97肝癌细胞模拟体外缺氧;将红色荧光标记的上述细胞(MHCC97-R)行肝脏原位种植并肝动脉结扎,构建体内缺氧模型.在此基础上,以RNAi技术敲除上述细胞内β-catenin基因,观察其对缺氧环境中肝癌细胞侵袭、转移能力的影响.结果 缺氧抑制MHCC97肝癌细胞增殖及MHCC97-R移植瘤生长,但增加其体外侵袭及体内转移.敲除β-catenin不能进一步加强缺氧对细胞增殖的抑制效应,但可明显减少由缺氧诱导的侵袭、转移.结论 缺氧环境中,肝癌细胞增强的侵袭转移潜能与β-catenin功能相关.     

Canonical Wnt/β-catenin signaling mediates transforming growth factor-β1-driven podocyte injury and proteinuria

Transforming growth factor-β1 (TGF-β1) upregulation occurs in virtually all chronic kidney diseases and is associated with podocyte injury and proteinuria; however, the mechanisms contributing to this in vivo are ambiguous. In vitro, incubation of podocytes with TGF-β1 induced Wnt1 expression, β-catenin activation, and stimulated the expression of Wnt/β-catenin downstream target genes. Ectopic expression of Wnt1 or β-catenin mimicked TGF-β1, induced Snail1, and suppressed nephrin expression. The Wnt antagonist, Dickkopf-1, blocked TGF-β1-induced β-catenin activation, Snail1 induction, and nephrin suppression. In vivo, ectopic expression of TGF-β1 induced Wnt1 expression, activated β-catenin, and upregulated Wnt target genes such as Snail1, MMP-7, MMP-9, desmin, Fsp1, and PAI-1 in mouse glomeruli, leading to podocyte injury and albuminuria. Consistently, concomitant expression of Dickkopf-1 gene abolished β-catenin activation, inhibited TGF-β1-triggered Wnt target gene expression, and mitigated albuminuria. Thus, canonical Wnt/β-catenin signaling mediates TGF-β1-driven podocyte injury and proteinuria. These studies suggest that Wnt/β-catenin signaling may be exploited as a therapeutic target for the treatment of proteinuric kidney diseases.     

Tubule-specific ablation of endogenous β-catenin aggravates acute kidney injury in mice

β-Catenin is a unique intracellular protein functioning as an integral component of the cell-cell adherens complex and a principal signaling protein mediating canonical Wnt signaling. Little is known about its function in adult kidneys in the normal physiologic state or after acute kidney injury (AKI). To study this, we generated conditional knockout mice in which the β-catenin gene was specifically disrupted in renal tubules (Ksp-β-cat-/-). These mice were phenotypically normal with no appreciable defects in kidney morphology and function. In the absence of β-catenin, γ-catenin functionally substituted for it in E-cadherin binding, thereby sustaining the integrity of epithelial adherens junctions in the kidneys. In AKI induced by ischemia reperfusion or folic acid, the loss of tubular β-catenin substantially aggravated renal lesions. Compared with controls, Ksp-β-cat-/- mice displayed higher mortality, elevated serum creatinine, and more severe morphologic injury. Consistently, apoptosis was more prevalent in kidneys of the knockout mice, which was accompanied by increased expression of p53 and Bax, and decreased phosphorylated Akt and survivin. In vitro activation of β-catenin by Wnt1 or stabilization of β-catenin protected tubular epithelial cells from apoptosis, activated Akt, induced survivin, and repressed p53 and Bax expression. Hence, endogenous β-catenin is pivotal for renal tubular protection after AKI by promoting cell survival through multiple mechanisms.     

TC-1 (c8orf4) enhances aggressive biologic behavior in lung cancer through the Wnt/β-catenin pathway

Background

The thyroid cancer-1 (TC-1) or c8orf4 gene encodes a 106-residue naturally disordered protein that has been found to be associated with thyroid, gastric, and breast cancer. A recent study has indicated that the protein functions as a positive regulator in the Wnt/β-catenin signaling pathway in human breast cancer. However, no research has been done in the area of lung cancer. Therefore, the goal of the present study was to confirm the relationship among TC-1, lung cancer, and the Wnt/β-catenin signaling pathway.

Materials and methods

The expression of TC-1 was immunohistochemically examined in 147 patients with non–small-cell lung cancer. TC-1–overexpressed and silenced A549 cells were infected using lentivirus and MTT cell proliferation analysis, and Matrigel invasion assays and scratch-wound assays were performed to confirm the biologic behavioral changes in different A549 cell subsets. The Wnt/β-catenin signaling pathway, key gene β-catenin, target genes of vascular endothelial growth factor, cyclin D1, matrix metalloproteinase-7, c-myc, and survivin were tested at the mRNA and protein level.

Results

TC-1 was detected in 97 of the 147 non–small-cell lung cancer primary tumor specimens, and its expression correlated with the TNM stage and regional lymph node metastasis (P < 0.01). In vitro experiments demonstrated that TC-1 expression affected both proliferation and invasion in the A549 cell line. Furthermore, expression of TC-1 protein affected the Wnt/β-catenin signaling pathway’s downstream genes, such as vascular endothelial growth factor and matrix metalloproteinase-7, at the mRNA and protein level.

Conclusions

TC-1 expression is associated with aggressive biologic behavior in lung cancer and might coordinate with the Wnt/β-catenin pathway as a positive upstream regulator that induces these behaviors.     

肝癌细胞仑伐替尼耐药的基因筛选及其通路研究

目的 基于CRISPR/Cas9技术筛选肝癌仑伐替尼耐药相关基因并探究其潜在关系。方法 应用CRISPR/Cas9 sgRNA全基因组文库技术结合Affymetrix表达谱芯片筛选肝癌对仑伐替尼耐药的相关基因。通过TCGA数据库分析这些基因在肝癌中的表达及预后的关系,最终确定采用THOC2为肝癌仑伐替尼耐药基因并用于后续研究。采用免疫组织化学（immunohistochemical,IHC）染色、Western blotting、RT-PCR检测THOC2在肝癌细胞株（MHCC-97H、MHCC-LM3、SMMC-7721）及仑伐替尼耐药/敏感肝癌组织中的表达情况。通过慢病毒感染构建高表达THOC2的SMMC-7721-THOC2肝癌细胞,采用免疫共沉淀（Co-IP）等技术探讨THOC2介导肝癌仑伐替尼耐药的可能机制。结果 发现7个与肝癌仑伐替尼抵抗密切相关的耐药基因,包括THOC2、CTNNB1（β-catenin）、MET（c-Met/HGFR）、HTATIP2、C10orf11、PRDX3、MAST4。TCGA分析提示THOC2在肝癌与癌旁中表达存在统计学差异,且与肝癌临床分期及预后密切相关。IHC染色、Western blotting、RT-PCR检测发现THOC2主要分布于胞核中,其在仑伐替尼耐药组患者中的表达水平高于药物敏感组患者;THOC2在高转移潜能的肝癌细胞株（MHCC-97H、MHCC-LM3）中的表达较在SMMC-7721中更显著;Western blotting、Co-IP进一步表明上调THOC2后Wnt/β-catenin通路下游靶点BAX、cyclinD1和c-myc蛋白水平显著增高,且THOC2与β-catenin存在相互作用关系。结论 THOC2基因高表达可能通过Wnt/β-catenin通路参与调控肝癌对仑伐替尼的耐药。